目的:研究罗红霉素胶囊在正常人体内的药动学与相对生物利用度。方法:采用反相高效液相色谱法测定10名志愿者单剂量po300 mg罗红霉素胶囊与罗力得片后的血药浓度变化情况，计算二者的药动学参数与相对生物利用度，以AUC0→∞与C_max/AUC为指标，用配对t检验法与双单侧t检验法分析两种制剂的生物等效性。结果:二者药-时曲线可用一室模型拟合，二者的K分别是0.0884 h^-1与0.0873 h^-1；t_max。分别是3.13 h与2.96 h；C_max分别是5.08μg·ml^-1与5.51μg·ml^-1；AUC0→∞是76.37μg·h·ml^-1与79.34μg·h·ml^-1。配衬t检验与双单侧t检验结果均表明:二者AUC0→∞与C_max/AUC0→∞均无显著性差异(P>0.05)。结论:罗红霉素胶囊与罗力得片为生物等效制剂，罗红霉素胶囊的相对生物利用度为96.26%。

OBJECTIVE: To study the pharmacokinetics and relative bioavailability of roxithromycin capsule.METHODS: The roxithromycin concentrations in plasma were determined by HPLC method following a single oral dose of roxithromycin capsule and roxithromycin tablet respectively given to 10 volunteers in a open randomized cross-over test. RESULTS: The concentration-time courves of roxithromycin capsule and roxithromycin tablet were conformed to an one compartment open model with a first order absorption. The K was 0.0884 h^-1 and 0. 0873 h^-1，t_max 3.13 h and 2.96h, c_max5.08μg·ml^-1 and 5 . 51μg ·ml^-1, AUC0→∞76 . 37μg·h·ml^-1 and 79.34μg· h·ml^-1of roxithromycin capsule and roxithromycin tablet respectively. There was no significant difference between the two formulations in the AUC0 →∞ and c_max/AUC0→∞.CONCLUSION: The results of statistical analysis showed that the two formulations were bioequivalent. The relative bioavailability was 96.26% of roxithromycin capsule.